- Cadiz
- Cairo
- Calcutta
- Caldwell
- Caledonia
- Cambridge
- Camden
- Camden
- Camp Dennison
- Campbell
- Canal Fulton
- Canal Lewisville
- Canal Winchester
- Canfield
- Canton
- Carbon Hill
- Cardington
- Carey
- Carlisle
- Carroll
- Carrollton
- Casstown
- Castalia
- Castine
- Catawba
- Cecil
- Cedarville
- Celeryville
- Celina
- Centerburg
- Centerville
- Chagrin Falls
- Champion Heights
- Chardon
- Chatfield
- Chauncey
- Cherry Fork
- Cherry Grove
- Chesapeake
- Cheshire
- Cheshire
- Chesterhill
- Chesterland
- Chesterville
- Cheviot
- Chickasaw
- Chillicothe
- Chilo
- Chippewa Lake
- Chippewa Park
- Chippewa-on-the-Lake
- Choctaw Lake
- Christiansburg
- Churchill
- Cincinnati
- Circleville
- Clarington
- Clark-Fulton
- Clarksburg
- Clarksville
- Clarksville
- Clarktown
- Clay Center
- Clayton
- Cleveland
- Cleveland Heights
- Cleves
- Clifton
- Clinton
- Cloverdale
- Clyde
- Coal Grove
- Coalton
- Coldwater
- College Corner
- Collins
- Collinwood
- Columbiana
- Columbus
- Columbus Grove
- Commercial Point
- Concorde Hills
- Conesville
- Congress
- Conneaut
- Continental
- Convoy
- Coolville
- Copley
- Corning
- Cortland
- Corwin
- Coshocton
- Covedale
- Covington
- Craig Beach
- Crestline
- Creston
- Cridersville
- Crooksville
- Croton
- Crown City
- Crystal Lakes
- Crystal Rock
- Cumberland
- Curtice
- Custar
- Cuyahoga Falls
- Cuyahoga Heights
- Cygnet
- Cynthiana
